nGammadionA cross formed of four capital gammas, formerly used as a mysterious ornament on ecclesiastical vestments, etc. See Fylfot.
Century Dictionary and Cyclopedia
ngammadionAn ornament on ecclesiastical vestments resembling the Greek capital gamma (Γ) in shape. Usually in the plural, four gammas in different positions being placed back to back so as to form a voided Greek cross, ╬. This ornament was formerly frequent on certain vestments of Greek prelates, and was also used on vestments in the Western Church. Also gammation.
In early Greek art the Swastika and Gammadion are everywhere, especially as embroidery on dress.